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Magnetic Viscosity as the Dominant Shear Force in Accretion Disks

Published online by Cambridge University Press:  19 July 2016

W. Kundt*
Affiliation:
Institut für Astrophysik Auf dem Hügel 71 D-5300 Bonn 1, FRG

Abstract

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Matter in accretion disks spirals inward because of angular-momentum losses due to intrinsic shear torques. For galactic disks, the accretion rates can be as high as 1M/yr, corresponding to a value larger than unity of the dimension-less viscosity parameter α. The required torques exceed turbulent ones by at least an order of magnitude; they can, however, be the result of magnetic tensions.

In fast-revolving, clumpy disks, magnetic pressures can exceed static gas pressures and approach ram pressures. Suggestive candidates for such magnetic dominance are the inner, near-rigidly rotating parts of galactic disks.

Type
4. Magnetohydrodynamics of Galactic Magnetic Fields
Copyright
Copyright © Kluwer 1990 

References

1. Peacock, J.A. (1987) in: Astrophysical Jets and their Engines, NATO ASI C 208, ed, Kundt, W., Reidel, pp. 171, 16 Google Scholar
2. Blitz, L., Fich, M., and Stark, A.A. (1983): Astrophys. J. Suppl. 49, 183 CrossRefGoogle Scholar
3. Kaelble, A., de Boer, K.S., and Grewing, M. (1985): A & A 143, 408 Google Scholar
4. Loiseau, N., Nakai, N., Sofue, Y., Wielebinski, R., Reuter, H.-P. and Klein, U., (1989): A & A , in press Google Scholar
5. Harnett, J.I., Beck, R., and Buczilowski, U.R. (1989): A & A 208, 32 Google Scholar
6. Sarazin, C.L. (1988): X-ray emission from clusters of galaxies, Cambridge Univ. Press, pp. 78,88 Google Scholar
7. Morris, M., editor (1989): The Center of the Galaxy, IAU 136, Kluwer CrossRefGoogle Scholar
8. Sanders, R.H., and Wrixon, G.T. (1973): A&A 26, 365 Google Scholar
9. Allen, D.A., and Sanders, R.H. (1986): Nature 319, 191 Google Scholar
10. Shibata, K., Tajima, T, and Matsumoto, R. (1989): Astrophys. J., submitted.Google Scholar